Spring roller-blind



. H. E. FOX. SPRING ROLLER BLIND. APPLICATION FILED SEPT. 4, l9i9.

Patentgd June 1, 1920.

HIE

FATENT QFEQ' I HAROLD EDGAR. FOX, OF NEWTOVT 1\l',. SYDNEY, I\TEW SOUTH WALES, AUSTRALIA SPRING ROLLER-BLIND.

Specification of Letters Patent.

Patented June 1, 19 20.

Application filed September 4, 1919. Serial No. 321,726.

ments in Spring Roller-Blinds, of which the following is a specification.

This invention relates to roller blinds of the type in which a sprin contained within the roller is tensioned by drawing down the blind and by reaction rewinds the blind when controlling pawls are released.

It sometimes happens that if a blind is released and gains considerable momentum, the controlling pawls do not operate and the blind races.

The purposes of this invention are to provide simple and effective means for preventing such racing, but permitting the actuation of the blind at reasonable and normal speed.

The invention consists in providing checking means comprising one or more spring control pawl-catches and associated detent or detents with which said catch or catches spring pressure. The invention also consists.

in the provision of a cylindrical'cap fitted on one end of the roller and over the pivot pin thereat, said cap carrying the pawlcatch or catches; and in the provision of a cylindrical sleeve carried by the roller-supporting bracket, and within which one end of said cap is housed, said sleeve carrying the detent or detents. The invention further consists in rotatably mounting said cylindrical sleeve on the bracket and providing a controlling spring therefor, so that resiliency is given to the detent and too sudden stoppage of the roller is avoided.

To fully explain the invention and the manner in which it may be employed, reference will now be made to the accompanying drawings inwhich- Figure 1 represents my invention applied to end of a spring blind roller, said end being that at which the non-rotating pivot pin exists. 7 v

Fig. 2 represents the end of the roller with cap carrying the checking means fitted thereto; and also shows separately the cylindrical sleeve attached to the bracket, said sleeve being partly broken away to show more clearly the internal arrangements.

Fig. 3 represents the end of the roller and the cap removed therefrom, disclosing the ordinary controlling pawls, with which my invention does not interfere, but is additional to. Fig. 4 is a sectional plan view of the construction shown in Fig. 1.

Fig. 5 is a vertical sectional elevation on line 5,5 of Fig. 4.

, tively on screws 15, 15 and normally held in inoperative position by leaf springs 16, 16 is suflicient to resist centrifugal force and maintain the pawl-catches in inoperative .position unless the speed of the roller, be-

comes excessive.

Referring to Figs. 1 to 5 inclusive, the bracket 18 is brazed or otherwise attached to a flanged disk 19 centrally forming a hollow, boss 20 which is slotted as at 21 to receive the pivot pin 11 of the roller (see Fig.

4). On the flanged disk is rotatably mounted a cylindrical sleeve 22 held on the said disk by having an annular inset as at 23 engaging one sideof the flange, and by lugs 24, 24 integral with the sleeve and bent over the other edge of the flange. Internally the sleeve carries a pair of detents 25, 25. The end of cap 9 enters the sleeve 22 when the pivot pin 11 engages its bearing slot 21, the pawl-catches 14, 14 alining with detents 25,

25 and engaging same when the speed of the roller is such as to create suflicient centrifugal force to cause said catches to move outwardly. At reasonable speed the pawlcatches are held inwardly by their springs and do not engage the detents.

It will be noted that engagement of the ment when the blind is drawn down at any speed. As before stated the sleeve 22 is rotatably mounted on the disk 19 and the engagement of the pawl-catches with the dc tents would tend to rotate it. This tendency is resisted by a spring 26, which gradually absorbs the shock and brings the roller to rest. Said spring 26 is connected to a lug 27 on the sleeve and to any convenient fixtu-re such as the bracket 18. 7

Referring to Fig. 6, the construction is the same as before described except as regards the flanged disk and sleeve. These latter elements are omitted and the bracket 18 is of more ordinary construction, being however terminally bent to provide a detent 28 with which either of the pawl catches 14, 14: engage under. the conditions before stated. It is to be understood that the springs 15, 15 exert sufficient force onthe pawls to resist the centrifugal tendency of the latter when the roller rotates at a normal speed. It is also to be understood that the, checking means herein described are in addition to and in no-way relate to the usual" controlling pawls prov'id ed'for holding the blind at any desired elevation.

Whatl claim and desire to secure ters Patent is g I The combination with a spring blindroller and a supporting bracket therefor of means for preventing racing of said roller in a direction to wind up the blind, com prising a pawlecatch pivoted on the end-of said roller, aspring normally retaining said by Letpawl catch ininoperative position, anda detent carried by said bracket andwith which pin of said roller, apawl-catch pivoted on the end of said cap, a spring normally retalmng said catch in lnoperatlve posltlon,

a detent carried by said bracket and with which said pawl engages when the roller attains excessive speed in the direction specified and centrifugal force causes the pawlcatch to overcome the pressure of the spring and move outwardly.

8. The combination with a spring blind roller and a supporting bracket thereforof means for preventing racing of said roller in a directiontowind up the blind, and I comprising a cap fitted" on .oneend of the 1 roller and apertured to take over the pivot thereof, a pawl-catch pivoted on the end of said cap, a spring normally retaining said catch in inoperative position, a cylindrical.

sleeve housing the end of the cap with'the' roller androtatably mounted on the supporting bracket, a spring resiliently checking the rotation of said sleeve, and in said sleeve a detent with which catch engages when the roller attains excessive speed in the direction indicated and centrifugalforce causes said catch to overcome the pressure of its retaining sprin and move outwardly.

Signed at Sydney, 23d day of July, 1919.

" HAROLD EDGAR; FOX.

ew' South Wales, this 

